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A204256 Permanent of the n-th principal submatrix of A204255. 2
1, 3, 19, 86, 1060, 13276, 215308, 3086544, 68937280, 1552257216, 40750688448, 987692033664, 31883024335104, 1036810188322560, 37597332892066560, 1285416947916933120, 54309158991453634560, 2309262618253981040640, 106842526312699253145600 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..35

MATHEMATICA

f[i_, j_] := 1 + Mod[i + j, 4];

m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]

TableForm[m[8]] (* 8x8 principal submatrix *)

Flatten[Table[f[i, n + 1 - i],

  {n, 1, 12}, {i, 1, n}]]  (* A204255 *)

Join[{1}, Table[Permanent[m[n]], {n, 1, 20}]]    (* A204256 *)

PROG

(PARI) a(n) = matpermanent(matrix(n, n, i, j, 1 + ((i+j) % 4))); \\ Michel Marcus, Jan 30 2021

CROSSREFS

Cf. A204255.

Sequence in context: A163431 A167242 A089621 * A015528 A183384 A050863

Adjacent sequences:  A204253 A204254 A204255 * A204257 A204258 A204259

KEYWORD

nonn

AUTHOR

Clark Kimberling, Jan 14 2012

EXTENSIONS

a(0) and a(18) from Pontus von Brömssen, Jan 30 2021

STATUS

approved

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Last modified December 6 10:12 EST 2021. Contains 349563 sequences. (Running on oeis4.)